PHOENIX - The first time 12 News viewers heard from Clint Van Zandt back in July 2016, when the former FBI profiler drew a rough sketch of the Serial Serial Shooting suspect.

This week, Phoenix police have arrested Aaron Saucedo, 23, and accused him of 12 shootings and nine killings in the string of violent crimes.

"He may well be playing a waiting game against law enforcement, fully realizing that law enforcement can only be leaning forward in the saddle for so long," Van Zandt said.

That was the time the trail seemed to grow cold for investigators. But in actuality, police were working the patterns identified by profilers, like where the shooter was likely to operate.

"Either someplace very close to their home or their residence," Van Zandt said.

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He went on to say that it is not unusual to be where they work or sometimes at a distant point and then start working their way back again. 

The first shootings in the 2016 string were in central Phoenix a few miles from Saucedo's home. The gunman then ventured farther west to the Maryvale neighborhood near 65th Avenue and Indian School. Then in August 2016, viewers heard Van Zandt caution against premature conclusions about who the killer might be.

"Eyewitness testimony many times is the worst possible testimony we can get," he said.

But he commended Phoenix detectives Monday for wading through more than 3,300 tips and identifying a crucial clue in the case.

"Witnesses knew the car that the shooter might have been driving: the dark-colored or black BMW," Van Zandt said. 

With the vehicle information and a sketch of a possible suspect in police hands, Van Zandt says FBI profilers then likely reminded detectives of another serial shooter trait.

"The believed shooter is quickly going to change his physical appearance," he said. "He's going to get rid of a weapon he may have had. He's going to get rid of a car he may have been driving."

That's exactly what Saucedo did after a mid-summer media blitz for information.

"He has told (detectives) that he did, after that ... changed his appearance and stopped driving his BMW," Phoeniix PD spokesperson Sgt Jonathan Howard told a packed Monday afternoon press conference.

And as for the gun used in the crimes, Phoenix police say Saucedo tried to get rid of at least one weapon during his deadly shooting spree by selling it at a pawn shop.

Saucedo has been charged with at least 26 counts in 12 separate shooting incidences, including nine fatalities.

MAP: See the Serial Street Shootings mapped out across Phoenix